We thank N. Li and D. Li for critical discussions. We thank L. Hui for providing the immortalized plasmid. We thank Genome Tagging Project (GTP) center for providing CENP-A-HAtag cell line. This study was supported by the National Key R&D Program of China and the National Natural Science Foundation of China (2019YFA0109900, 2020YFA0509000, 31821004, 32030029, and 31730062), and partly supported by China Postdoctoral Science Foundation (2021TQ0329).